问题补充:
--- do you go shopping, Mary?
--- Twice a week.
A. How often
B. How much
C. How far
D. How long
答案:
(答案→)A. How often
B. How much
C. How far
D. How long
解析:疑问词辨析。How often多久一次;How much多少钱; How far多远;How long多长。根据答语,一周两次,可知询问的是频率,故用how often来提问。选A。